As a Linux user, I have taken the icc profiles for my Epson Stylus SX445W from its OS X and Windows driver installers.

When I put both icc profiles (70.3 KB each) in ~/.color/icc/, Scribus does not show any of them in the "Preferences -> Color Management -> Printer" pop-up menu. I use Scribus 1.4.5, but I've also tried out 1.5.6.However, I have a smaller monitor icc profile taken also from Windows (8.5 KB). When this file is in ~/.color/icc/ I get an "Epson RGB" profile in the RGB pop-up menus. But, if I move it out from the folder the menu entry disappears, so it's not a problem of Scribus not detecting the ~/.color/icc/ folder.